During a mid-October expedition, NASA's Operation Ice Bridge discovered a crack running across the floating ice shelf of the Pine Island Glacier in Antarctica. The team's scientists say that in the coming months, the glacier will probably calve, producing a 310-square-mile iceberg, part of a regular, cyclical process. This winter, a National Science Foundation-backed expedition will be drilling at a site nine miles from the crack to install equipment with which to monitor ice sheet-ocean dynamics. That research site, planned before the discovery of this crack, will hopefully be in place by the time the calving occurs.

Image: NASA.